Internal-combustion engine



COPY

May 4, 192.6.

15183570 G. K. DAvoL Y INTERNAL coMBusTroN ENGINEl I Filed Augusfzylsazl 5 sheets-sheet i May 4 1926. 15839670 G. K. DAVOL INTERNAL COMBUSTION ENGINE 9 Filed August 6, 1921 JQ 3 Sheets-Sheet 2 f May 4,1926. l. 1,583,670

` G. K. DAvoL INTERNAL COMBUSTION E-NGINE v v Filed August 5, 1921 3 sheets-sheet s Q, N l l 6J- r\ g ou m.

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-cylinder or combustion chamber.

v and-6--6 of Patented 4, 1926.`

lUNITED STATES PATENT, ori-icav GEORGE K. DAVOL, OF

SAN FRANCISCO, cALIsoRNIA,. AssIGNoR To cHAuLEs A.' l:mou/'1a. or HINsDALE, ILLINOIS. j 1

. Application led August 6, 1921. Serial No. 490,218.

T all whom'tmay concern.' v

Be it known that I,` Gr"aonc11v K. Davon, a

`citizen of the United States, residing at San Francisco,l in the lcounty of San Francisco and State of' California, have invented a Certain new ,and useful Improvement in Internal-Combustion Engines,

descriptiomrefercnce being had to the' accompanying drawings', forming a part of n this specification.

plication of mechanism. j o

'While the essential features of my 1nven.

tion can be embcdiedin forms of engines operatin on .the four stroke cycle `or on the 'two stro Ie cycle, in the embodiment of the invention herein disclosed, oper-ation ofthe four stroke cycle is assumed, and I have not the manner of applying the features of the invention toan engine operating on the twostroke cycle as such application is obvious. My invention has particularly to do with an engine in which a separate'air compressing cylinder is provided. for each working cylinder of the engine,

or compressed a1r for the injection'of the fuel intothe working In the accompanying drawings: 4 Figure 1 is a sectional view of the working and compressing cylinder of an engine embodyi- 'Figure 2 is a sectional view of two adjacent compressing-cylinders taken at right angles to the section shown in Figure 1.

Figure 3 is an enlarged sectional view of the fuel. injecting valve.

Figure 4; is an outsi the fuel injectin valve, and

Figures 5 an 6 are ,cross-sections ofthev fuel injecting` valve taken on the line 5-5 igure 3 res ectively., In the embodiment vo my' invention selected for'illstratiom a main cylinder-cast! ing 1 is provided, in whichv are formed a working cylinder 2 and a compressing cylof' which the following is a full, clear, concise, and exact cylinder casting and which'l at ,the

for the purpose of` ng the principles of my invention.

de View of the naafinder 3. A working .piston 4 connected with the end of connecting rod 5 reciprocates in the working cylinder, and a compressing piston 6 similarlyconnected by the rod 7 to a crank on thecam shaft of the engine, re- G0 ciprocates in the compressing cylinder. Figure'2 shows two adjacent compressing pistons 6 of a multi-cylinder engine, connected by rod 7 to the cam shaft 8. Above the mhin is a cylinder head 9, nd 65 a ove vthe hea a valve tapped frame 10A and a final cover 11 are placed. The cylinder casting 1, head, 9, tappet carrying frame 10, and cover 11 are all secured togetherby studs 4or bolts (not shown). I0 A ,spring held air admlssi'on `valve 12 is l carried in -a cage or seat 13 in ari-opening formed in the head `9. This cage 13 'is held down against the pressure within thecylin der 3. by a` screw collar or gland 14 bearing 75V I on packing 15 to force the cage against a seat .or footing 16. An inlet passage Aor manifold17 supplies air to all the working cylinders of the engine. The main linlet valve 18 of the working cylinder 2 is shown 80 'I in dotted lines in Figure 1 asit lies behindv the section taken. Thisinlet valve 18 is l operated by the tappet .19l pivoted on the shaft 20 and derivin-g motioiiom the tap` pet rod 21, Figure 2 shows the rod 21 and 86 tappet 19 for the opcrationof both inlet and exhaust valve of two vadjacent working cylinders. '4 4 I r The inlet valve 18 is supplied with air fromrthe passage 17 by a branch passa e indicated by dotted lines 22 (see Figure l A passage or openin 23 allows air to flow from the passage 17 t irough passages in the `valve case 13 to the air vadmission valve 12 and through the same into the compressing 05' cylinder 3 on the suctionstroke. In this manner` both the working cylinders and the l air compressing cylinders Yare supplied with Aair from one passage or manifold 17 and so are equally elfected by any"throttling' or 100 alteration of the density o'f the air within the passage-17. d

In Figureul Il have shown the passage 17 connected to an intake pipe '17 in which is pvotally mounted a lthrottle 17 of any105 suitable construction.' The throttle 17". is

adapted to control the charge admitted through the .passa 'e 17 in a manner well known to those skilled in the present art.

Obviously, as will become more apparent as 11.0

the-present description progresses, by varyl ing the mass of the'iuid enteringthe passage 17 the mass of both the branch charge andthe main charge coming from the passage 17 will be varied without varying the' ratio between them,

The cam shaft 8 is carried in bearings 24 and 'on each side of each ofthe cranks which operate the compressing pistons carries a cam 25.- These cams operate sliding.

blocks 26 suitably held iii-guides, which blocks in. turn operate the tappet rods 21.

. By positioning the `compressing cylinder for each main cylinder between "the valve actuating mechanism for. that cylinder-a very compact, symmetrical, and convenient arrangement of the assembled partsxis lobtained. y

-At the end of the compression stroke of the compression pistons, in whichV position the compression piston` 6 is shown in Figure 1, there is still left a considerableclearance space. within the compression cylinders,

' within which the air entrappedA and com' pressed is held. jThis body of airl compressed within this clearance space of any one ycompression cylinder is used to atomize and inject fueLinto the corresponding workino cylinder or combustion chamber. n'using the term cylinder in this de. seription and in the claims which follow I intend to designate the chamber which, to-

' gether ,with the piston Afitting a portion of it,

sustains'the pressure of air or gases held, compressed or expanded within it, whether such chamber' be actually of cylindrical form or'other'form. The extension'of the .compressing cylinder into the cylinder head 9 I therefore refer to as la -part of theI co1n of the compression cylinder, although its form need not be cylindrical. f

.pression cylinder, or as the clearance'spac'e Passing4 through the clearance `space is an injectlor valve body 27 having a'I central bore; 28 and a. fuel nozzle'29 in said bore.

This' fuel nozzle. is secured to the body byits end anve and screws 30, which screws pass through 31 and` enter the body 27. Passage of air from cylinder 3 to bore 28 is suitably con'- .trolled by a delivery valve. 33 screwed at one end tothe body 27 and normally clos-v ',fing port'32.

A recessed cap 34, (see Figure\ 3) is screwed to the inner end of the body. 27, andl on its external end bears against and makes` as ti ht contact withthe end of the hole` orme in the cylinder head 9 `to receive it. An extension passage 35 connects with a passage 36 opening into the working c linder 2,

within which passa e is an adjusta le needle 37. The shank of t is needle tits passa e 36 and-is threaded for screw adjustment t ere# in, /as shown in Fi u re 1, to adjust the conical inner end of t e needle relative to the gland Y 41 secured. b

thelange and the connector.'

vthe position shown in.- Figure 3.

contracted inner end of the passage and vary the area of the final orifice communieating with the cylinder 2. s 1 Within the recessed cap 34 a.' valve stop 38 see Figurev 3) having-an axial boreand sma l radial holes 39. The end 'of the lbody entering the recessed cap 34 forms `a seat for the check .valve 40, which'. loosely. fits the bore of therecessed cap 34 and plays be 'tween its seat and the end of. the valve stop 38. The valve is provided with small holes near its edge, through which'holes the v e air and atomized fuel may pass when the valve is'of its seat.

The injection valve body-27 isy heldin placeand forced ,in against` the head 9 by studs to the'head 9, glandring- 42 an ack-ing 43 bearing against the flange 44. (gland 41 (see Figure 4) has an inverted U-shape to permit` extension of the connector 31 for connection to, the fuel pipe 45. The fuel is forced through this pipe 45 at the proper time and in prper y contact with the valve. The 'inner face of the compressing piston 6 is recessed by a-two diameter hole for theaccommodation of a tappet 49. vThis tappet is forcedupward.

by lthe strong 'springl surrounding its. shank. The tappet is held down in adjust. able position against the action of the spring',- by the adjusting and retaining screw 51.

. Atjthe end of the up -stroke of piston 6, A the tappetv 49 comes into contact with and lifts the lower projecting end vof the plung` ers 48,"which in turn lifts the valve 33 off its seat, permitting the aircompressed within the clearance space above the pistony to rush through the port 32 intol the annular space surrounding the nozzle 29. Therethe air picks up the fuel Vpreviously deposited andc'arries it through the passage 28, valve 40, hole 39,'and passages A35 and 36 into the `Working cylinder 2, atomizing-thefuel by its velocity throu h these. various passages andthrough the nal -atorn'izin orice surl,

rounding the point of the-need e 37 p I t will be noted. that one side'of the topl ofthe tappet is b eyeled off or inclined This is an important feature asit enables f tlievalve body'27 to be inserted in place even when the piston 6. is `atthetop of its stroke, as the plungers 48 striking the inclined side of the tappet as, the'body' is pushed into place, slide up the incline into The air compressed by piston 3 expands again in the clearance spacey in which it was originally compressed and the resultant cooling tends to lessen the importance of water jacketing this part of the device.

With the direction of the jet of atomized fuel and air entering the working cylinder 2 o r with thetiming o this injection, my present invention is'less essentiallyv concerned. The entering jet may, be arranged toproduce an' intimate mixing of the entire charge ivithinthe working cylinder as in the arrangement disclosed by the drawings or it may be so introduced as t0 produce a stratitied charge. o

The 'timing of fuel inject-ion isregulated b iiig crank of the cam shaft 8 and the crank of the Working piston, which position may be chosen to suit the timing desired. Thus the invention may be embodied in an engine in which the fuel is injected into the Working cylinder before or during the compression stroke and ignited by an electric spark, or it may be embodied in an engine injecting the fuel at nor near the end of the compression 'stroke of the working piston, ignitionA being .obtained through the heat of compression orotherwise.

When the invention is embodied man engine injecting the fuel previous to or dur-l ing the early part of the compression stroke arid the entire contents of the cylinder is in-y timately lmixed,a certain limited range of vvariation of the proportion of fuel to airis required, andvthis'may ordinarily be maintained with varying loads through throttling the air supply to the intakel passage or manifold 17, and simultaneously adjusting the amount of fuel supplied.` `Wlien the main air supply is so throttled to any considerable extent, it may become under'certain conditions a matter of importance tol also reduce the amount of air used fori injecting and atomizing the fuel. By drawing the injection airfrom the same source, passa e 17, as that supplying .the working lcylin er, ythis reduction is automatically taken care of.

The directionof .jet andv the form of the part on which it imping'es ma be chosen so as to promote an extreme tur iilence ofthe cylinder contents, and the surface on whidi the jet irst impinges may be so designed and arranged yas to be maintained through 'the heat of combustion above a certain minimum temperature, and at the Sametime be maintained below a certain maximum temperatui'eby the cooling action'of the impinging jet of atoiiiized fuel and'aii".v Such a surface at the proper temperature willv act to s'sist in vaporizing vthe fuelprevious to ig- .i'fnition Without further elaboration, the `forego-l ing will so fully explain the gist of my invention, that others may, byrapplyng curtherelative positions of the air compressrent knowledge, readily adapt the same for use under various conditions ofservice. It will, for instance, be -obvious, that plungers 48 might be made Without heads and carriedv on the piston,or tliataii 'entirely dierent valve might be substituted for the iap valve 33 illustrated as the preferred form of this These and many other l. In an internal combustion engine ,o

the fuel injection type, a Working cylinder, a compression. cylinder, a piston reciprocating in 'said compressing cylinder,

from the movement of said compression piston.

2. working cylinder, a piston and cylinder for compressing Y'air to inject fuel, a delivery valve located entirely within said last inentioned cylinder, and an operativeonnection between said valve and said piston.

3. In an internal combustion engine,` a workingl cylinder, a second cylinder for compressing air to inject fuel, 'a delivery passage connecting withV said compressing cylinder, a valve for Aclosing said passage, a piston moving in the compressing cylinder,

and means operated by contact with said a port .fordelivering air from said compressing 'cylin- In an ,internal combustion engine, a

piston for opening said valve against the' pressure in said cylinder.

4. In an internal combustion engine, a

working cylinder, a second cylinder-for coinpressing. air to vinject fuel, a delivery passage leading from said 'compressingeylinden a flat flexible valve overlying said passage to covei'the same, a piston in said compressing cylinder', and means providing an operative contact connection between said valve and said piston.

5. In an internal combustion engine, a Working cylinder, a second cylinder for compressing air to inject fuel, a delivery valve holding body passing through the clearance space of said compressing cylinder, a passage leadingfrom said valve holding body to said working cylinder, a valve supported by and seated on said valve holding body, a piston v in said compressing"cylinder, and

means for operating said valve through contact with said piston.

6. In an internal combustion engine, a

.working cylinder, a second cylinder for conivpressing air to inject `fuel, a'delivery valve holding body Within the clearance-space of said compressing cylinder, a flat flexible valvev seating on said body,-plunger means passing through lsaid body to act againstthe seatinOr face of said valve. and a iston D l v cylinder, and a nonreturn check valve carried by said delivery valve holdingbody arid placed lin said passage, said body extending into the compression'space of said comprese sion cylinde l 8. -In an internal 'combustionv engine, a

Working cylinder, a cylinder for compressl ing air to inject fuel, a delivery valve holding body having a passage therein, said body passing through the clearance space of saidcompressing cylinder, andv a non-return check valve placed in said passage.

9. In an internal combustion engine, a Working cylinder, a cylinder for compressing .air to inject fuel,'a delivery valve holding body having'an axial passage therein and passing through the clearance sp-ace of said compressing cylinder, anda source of fuel i supply connecting with the outer end of said axial passage, the innerv end of said axial pa-'a e communicating with said Working cylin er.

10. In an internalcoinbustion engine,- a working cylinder, a cylinder for compressing air to inject fuel, an air`- inlet passage supplying air to said working cylinder, an

inlet valve opening into said compressing cylinder, and a connecting passage between said inlet valveand the tione j v 13. In an inte`rnal combustionengine, a' Working cylinder, a cylinder.- for compresspassage supplying the said Working cylinder.

11. In -an internal combustion engine, a working cylinder, a cylinder for compressing air to inject fuel, a piston in said compressing cylinder,l an adjustable member on f the inner face of said piston, and `delivery valve mechanism open `to the interior of said compressing cylinder and arranged to be unseated by said adjustable member.

. 12. In an`.internal combustion engine, a

working cylinder, a cylinder for compressing air to inject fuel, a passage parallel to the axis of and opening into the working cylinder for delivering fuel thereto, and a delivery valve holdin body passing in open connection with the c earance v"space of said compressing cylindelgrsaid body having an axial assage 'connecting with said first-menpassage.`

iiig air to inject fuel, a passage parallel to the axis of and openinginto the working cylinder for delivering fuel thereto, anda delivery valve holding body passing through the clearance Space of said compressing cylinder, said body having an axial passage connecting with said rst mentioned passage.

14. '.lhemetliod of controlling an internal combustion engine of the injection "type,

the fuel injection type, a compressing cylin.

der and piston, and a delivery valvestructure inside the clearance space of said cylinder. V

16. In an internal combustion engine of the fuel injection type, a compression cylinder and iston, and a delivery valve stlructureinsi e the clearance space of said cylinder, saidvalve being automatically operated lby con-tact with said piston.

17. In an internal combustion en ne, a Working cylinder, an injectionconduit leading thereto, me ns defining a space surrounding a' portion of said conduit, means for coinpressing air in to said space, a lateral port in the portion of said -conduit f passing.

through said space, and a delivery valve'con-v trolling said port. y

18. In an internal combustion engine, two

cylinders, a valve in one of thesaid cylinders fand an injection conduit assing through the clearance space of one cy inder communil eating withthe sai'd cylinder throughthe inder.

19. In an internal combustion engine, two

cylinders, an injection conduit passingy through the clearance space of one cylinder said valve, and lopening' into the other `cyll and opening into the other cylinder, means for'depositing liquid fuel at an intermediate 20. The method of 'controlling an internal' combustion engine of the injection type, coin- Vprising'independently compressingl an in-jec- "tion air charge for each main charge', and

varying the mass of both charges without varyin the ratio between them.

21. n an internal combustion engine, a working cylinder, a second cylinder fo'rconiressing air to in'ect fuel, a delivery passage eading from sai compressingcylinder, and

-iio

a Hat flexible valve overlying 'sai-d passageto-v cover the same.

-In witness whereof, I hereunto subscribel .my naine this secondday'of'Aug'ust, 1921.

GEORGE .K. Davonv 

